Approximately 6% of plant species have sexes separated by individual. A small fraction of those may change sex during their lifetimes based on environmental cues. While the presence of reproductive structures such as gynoecia and androecia determine sex, there may be sex-based differences in physiology or life-history traits. This variation may result from natural selection optimizing traits in diverging ways for females and males. Spatial segregation of sexes or nonconformity in microclimate can further complicate studies of sex-based dimorphism and physiology.  Here we report preliminary data on physiological differences in the sexually labile tree, Acer Pensylvanicum, a native understory tree. Individuals in this species may switch sex throughout their lives based on environmental cues and therefore offer a unique chance to investigate differences in sex-based physiology. We present field data on demography (size, flowering sex, health, growth, and mortality) and physiology (photosynthetic rate, stoichiometric ratios, and fluorescence). We show that both season and sex impact physiological and demographic parameters and that the patterns persist across seasons.